January 22, 2014
The good news for Iowa gardeners is that there are many orchids that flower indoors in the winter, after spending a typically warm and humid summer outdoors, “charging their batteries” as surely as solar panels gather and store energy. Master orchidist and Greater Des Moines Botanical Garden volunteer Gary Heggen calls out the following as some of his favorite orchids for winter bloom:
Angraecum sesquipedale, the Christmas star orchid, has waxy white flowers, each having a nectary upwards of a foot long. When Charles Darwin first saw it he predicted there must be a pollinator having a similarly long proboscis and 41 years later a hawkmoth proved him correct. The plant is comprised of stiff leaves in two ranks, like a German iris, and handsome in its own right. Angraecum Memoria George Kennedy in the Botanical Garden collection has shorter nectaries but is otherwise like the Christmas star orchid.
xAscocenda hybrids: These small plants with braggadocio flowers represent crosses between the genera Ascocentrum and Vanda. The stiff leaves grow in two ranks on an upright stem and the long-lasting (up to six weeks) flowers come in hauntingly beautiful colors; some also have a tesselate pattern on the petals, not seen in any other orchids other than the vandas.
Many orchids in the Cattleya alliance bloom in the winter. These include Brassavola, Cattleya, Epidendrum, Laelia, Sophronitis and hybrids often known by initials instead of the parents' full names, for example: BLC stands for Brassavola x Laelia x Cattleya; LC stands for Laelia x Cattleya; and then there's xPotinara, a quadrigeneric hybrid created in 1922, that combines Brassavola, Cattleya, Laelia and Sophronitis; and finally, xYamadara, created by crossing a BLC and an Epidendrum. By any name these are orchids with exceptionally showy flowers and pseudobulbs (excepting some epidendrums) that suggest their need for medium to high light in summer, their season of regrowth.
Cymbidium is a genus of terrestrial (growing in the earth versus in the air) orchids having clumps of grassy leaves and spikes of long-lasting, waxy flowers in dreamy colors. A vigorous, mature cymbidium may send up numerous flower spikes successively over a period of several months. Grow cymbidiums outdoors in the summer and do not bring them indoors until night temperatures have fallen to about 40 degrees F.; without this chill, they are reluctant to bloom. For best flowering and long-lasting bloom, situate cymbidiums indoors in a cool room such as a sun porch with temperatures between 50 and 65 degrees F.
Dendrobiums typically send up thick, moisture-holding stems clothed with attractive foliage, topped by spikes of long-lasting flowers, typified by the many different colored Dendrobium phalaenopsis (not to be confused with the separate genus Phalaenopsis). In D. nobile the flowers appear all along the upright stems, putting on an incredible display on a relatively small plant. After a summer of sun, water, fertilizer and fresh, moist air, the nobile dendrobiums need cool temperatures in the fall (50-60 degrees F.), no fertilizer and little water, so that the new growth ripens. Beginning in the New Year, as days lengthen, increase watering and temperatures to bring on the flower buds. Without the dry, cool time in autumn, instead of flower buds forming all along the stems the new growth will take the form of keikis (Hawaiian for “baby”) that form air roots, after which time they can be cut from the parent and potted on their own.
The ladyslipper orchids belonging to the genus Paphiopedilum are among the most easily cultivated as all-year houseplants in any window having bright diffused light but not much direct sun. Some have silver-mottled leaves. Rarely exceeding 18 inches height even in bloom, they are also choice for growing in a fluorescent-light garden.
Phalaenopsis is from the Greek word for moth, which is what the early plant hunters thought they saw in the canopy of the rain forest. Tissue culturing has made these orchids as widely available as African violets, at prices generally ranging between $10-30. They often bloom for months on end in the same light and temperatures suited to human comfort. The plants need little direct sun, only bright reflected light. Recent introductions are miniature with flowering scapes about 8 inches tall above petite plants growing in 2-inch pots.Phalaenopsisdo not have moisture-storing pseudobulbs, so they need to be kept evenly moist—but never left standing in a saucer of water.
Several other orchids in the Botanical Garden collection bloom in the winter, including Lycaste, Masdevallia and Zygopetalum. Experience the floral wonders of the tropics any day this winter by visiting the conservatory and the Gardeners Show House.
One last word: What's the scoop on watering orchids with ice cubes? It's a method that hobbyists have used for years, to assure adequate but not excessive moisture, the rule of thumb being three ice cubes per plant once a week. Now the idea has been trademarked; for details visit justaddiceorchids.com.